PROJECT SUMMARY Olfactory disorders such as anosmia have received little attention relative to other sensory deficits. Identifying genetic alterations that lead to blindness and deafness has been critically important for developing gene therapies, in which a faulty gene is replaced with a working one, for both disorders. Over 100 altered genes have been discovered in patients born without hearing and over 200 genes are implicated in patients born without sight. These numbers are in stark contrast to the number of genes implicated in congenital anosmia; to date, researchers have identified only two genes associated with congenital smell loss. Our lack of understanding of congenital anosmia prevents many anosmics from knowing if their condition is acquired or genetic, temporary or permanent, and provides them little hope for diagnosis and treatment. This project will recruit patients with congenital anosmia and use exome sequencing to identify genes underlying this disorder.